Fortune plango vulnera stillantibus ocellis
by Lady of Sandwiches
Summary: S4 AU / In an attempt to break Sam away from the debilitating effects of demon blood (and, subsequently, Sam's addiction), Castiel offers something in exchange: He will train Sam to use the gifts he was born to wield with angel blood as the conduit instead. For sassysanta2012. *SEE PROFILE FOR MORE INFO*


Castiel believed himself to be prepared. He had known that he would eventually come face to face with the Boy King, given that he and Castiel's charge shared such close quarters. So he was aware, in the town that was doomed to die either at the hands of Samhain or the justice of angels, that he would meet Sam Winchester. It was unavoidable.

The angels had told him what to expect. "He is evil," Zachariah had said, "using the demon Ruby, drinking her blood to augment his evil powers. That boy has been defiled by Azazel, marked by Lucifer. But," and here he had sighed, "he is the Righteous Man's brother. And Dean Winchester is notoriously difficult when it comes to his brother." Castiel, in his own private thoughts, believed it would be a more just cause of action to kill the boy king. If this boy was indeed destined to bring about the end, would it not be more fortuitous to kill him now, and spare God's creation? But he had been ordered not to, under any circumstances. It puzzled him, but he did not question it. It wasn't his place to question it.

Armed with thoughts of Hellfire and brimstone, of righteousness and the victory of good over evil, he thought he was prepared to meet Sam Winchester.

He was utterly unprepared for what he saw.

Instead of something ugly, he saw something beautiful: a boy, with soft hair and beautiful bones, tall and strong. His eyes were wide with delight, and even as he blasphemed with the name of the Lord, awe flooded his entire being. He saw goodness and evil at war within this boy, the force of his will and the force of his destiny fighting for control. At that precise moment, his will was stronger. Castiel saw a good man who had been dragged by the hair into a role that he had no wish to play. It saddened him, and he pitied this boy for the things that he would have to do.

Sam's will may have been formidable, but destiny was relentless. It could not be stopped. It could not be overcome.

Sam's hand was hot to the touch, and Castiel could not pull away, even as his grace hissed and Sam's blood recoiled. Castiel could feel everything in that hand; the raw power pooling in the tips of his fingers, the confusing tide of emotions washing over him, the small spark of twisted grace that named him the Morningstar's. He wondered what it felt like to Sam.

"The boy with the demon blood," he said, to remind himself of what he was up against, rather than to point an accusatory finger at Sam. "Glad to see you've ceased your extracurricular activities." Castiel knew that Sam had lied to Dean about the demon blood. Of course he knew. He could feel it under Sam's skin, hot and thick and sickly. It felt _wrong_; the blood in those veins was not meant for someone as beautiful as Sam Winchester.

Castiel had been told to pay Sam no heed - his role in the coming days would be dark and full of despair, but ultimately necessary to stop the Apocalypse. He should focus on his own task of preparing Dean for the future ahead.

The palm of Castiel's vessel tingled with the echo of Sam's power, even hours later. He could not forget the boy with the demon blood even if he greatly wished.

Castiel observed the proceedings of the night with great interest. The demon Samhain was an immensely powerful one, legendary in his reign of terror, even to the humans, diluted though their precautionary traditions had become. And Sam Winchester was holding him at bay, overpowering him, even. The sharp sound of Sam's power echoed across the hallway at a decibel too high for humans to register. The air _twang_ed, as if a taut string had been plucked, vibrating with the force of Sam's focus and intensity. Samhain was brought low, forced to his knees before Sam, curses and smoke pouring from the demon's mouth. Sam was steadfast.

But he was more than simply unruffled, he was - unmoved. Exorcising a demon on the level of Samhain should have drained Sam, should have left him near dead from the effort, but Sam was fine. More than fine, he was completely unaffected. Not a single sign of strain was visible on him. Such a thing was unprecedented, not to mention extremely worrying. Sam could not have reached this level of power with only the demon Ruby's assistance. Unless his power was simply growing too quickly to be contained.

What a sobering idea.

_He deserves more than what he has been given. _The thought crossed Castiel's mind, and he frowned. It wasn't that he disagreed with it, it was that he wasn't sure where the thought had come from. But it was true. Sam Winchester was a cursed boy with a cursed destiny, through no fault of his own, and even as he strove to avoid it, he was crashing headlong towards his doom.

Orders and words of necessity flitted through his mind, but Castiel ignored them. Sam and Heaven were aiming for the same goal - kill Lilith. The difference between the two was that Sam had both the power and the drive to do it sooner, and more efficiently.

He was resolved. He would assist Sam in his quest for vengeance, and save God's finest creation.

* * *

The first task was to dispose of the demon Ruby. He found her lurking outside the Winchesters' motel, and he smote her where she stood. The girl was not given time to scream, and Castiel noted that the human body did not have a soul inhabiting it. Demons didn't seek out empty bodies when they delighted in tormenting the souls inside; he supposed that Sam must have specifically asked her to find an empty body. He was irrationally pleased by this.

He heard Sam's voice through the motel wall, angrily snapping, "Ruby, I need you. Where are you? Call me, _please_." Castiel blinked, and he was inside of the motel room.

"The demon Ruby can no longer help you." Sam jumped nearly three feet in the air, whipping around in surprise.

"What the he- Castiel? What are you - "

"She is dead, and I have removed that temptation from your path."

"You - you _killed _Ruby?"

"Yes."

Sam let out a shocked breath, as if it had been punched out of him. "Jesus," he swore softly, dragging his hands through his hair. Castiel frowned; it was a testament to his change of heart concerning angels that he did not apologize for blaspheming. Sam was pale, shaking, not from anger, but from early signs of addiction, Castiel realized. How fortunate that he had cut Sam off now, and not let this particular course of destiny play out.

"Cas," he said again, with shaking hands outstretched, "why the hell would you do that? She was helping me, making me stronger!"

"I know what you two were doing, and it was wrong." Sam may have been angry now, but Castiel would make him see reason.

"I know it was wrong!" he shouted. "I don't care if I'm going to Hell, I have to stop her!"

"I am not here to stop you, Sam."

That made him pause. "You're not?"

"On the contrary, I am here to assist you," Castiel confirmed, stepping closer. Sam looked as if he were about to fall over, from exhaustion, or shock, Castiel wasn't sure. But he was ready, should Sam need help. "You're right - Lilith has to be stopped. As of now, you are the only human with the power to bring her down. The demon blood that you were drinking," and Castiel tried not to let his lip curl in disgust at the thought of someone so pure and good willingly ingesting such a vile substance, falling victim to its addictive properties, "provided you with a quick boost, but as you can see, the effect wore off quickly."

"I can't," Sam swallowed thickly, "I can't use my powers without it. I've tried - they just don't work."

"You can," said Castiel, "and I will show you how. When the demon blood works itself out of your body, then we will begin."

"Begin what?" Castiel didn't answer. Uriel was calling him to report, and it took all of his focus to ignore the summons. He turned to leave, but was stopped by Sam's hand grasping the sleeve of his coat. "Cas, I... how will I find you?"

He turned back, covering Sam's hand with his own again. It was a gesture of comfort - he had learned that from the memories of his vessel. "Have faith," he urged, "and when you are clean, pray to me. I will come." He winked out of existence, ignoring the pull of Uriel's command.

The angels would not approve of this plan, but Castiel was willing to go against the laws of Heaven to do what needed to be done. He supposed he was very much like Sam in that respect.

* * *

Four days later, Castiel summoned Sam to an abandoned warehouse in their town of the week. "So, uh, Castiel," Sam called out to the empty room, "I'm here. Dean's asleep - he came back in completely smashed and I put him to bed, so..."

"Hello, Sam." Sam jumped as Castiel stepped out of the shadows.

"H-hey, Cas." Castiel reached out with his grace for a quick diagnosis - all healthy. The demon blood was completely out of his body. He was still pale, but Castiel suspected that was more due to lack of adequate sleep than the effects of a severe addiction.

"Are you ready to begin?"

"Begin what? Cas, you're being really - "

"Give me your knife." The voice that Castiel used left little room for argument, and Sam handed it right over. "Your powers originally came from Azazel," Castiel began, rolling up his sleeve. "By demon blood they were given, and with demon blood they can be used."

"Yeah, and then you killed the only demon who wanted to help us," Sam retorted, gesturing wildly with one hand. "What do you want me to do now, kidnap every demon I can find, kill the person inside, and drain them dry?"

That was the last thing that Castiel wanted Sam to do, and he was glad that Sam agreed. "However," he continued, slicing neatly across his palm, "angel blood can be used as an equally effective conduit."

"What? Cas - I don't - "

Castiel held out his bleeding hand to Sam, an offering for him to take as he wished. "Using my own blood as a power source, I will train you to use your gifts in the most efficient and effective way for the days to come." Sam was, predictably, floored by this pronouncement. Castiel took his silence as a sign to continue. "Angel blood is similar to demon blood only in its power-storing properties. You will suffer no adverse effects of addiction, and, eventually, you will no longer have need for it, being able to control your power all on your own."

"Castiel," Sam said softly, eyes beginning to shine, "I'm not going to drink your blood. Thanks for trying," he slid his hands inside of his jacket pockets, shoulders slumping in a defeated air, "but I'll look for another option."

"There is no other option," Castiel insisted.

"I'm not going to drink your blood! I'll just - I'll find other demons, and I'll use them - "

"No," he interrupted, letting his wings unfurl. They could not be perceived in the visible spectrum of light, but Sam's eyes focused on a spot over Castiel's shoulders, and he flinched, shrinking back.

"Who's going to stop me?" he asked, but if the question had originally intended to be fiery, hot-blooded and indignant, he failed, false bravado doing nothing to cover the tremors in his voice. "You?"

"Yes." The air around them vibrated, the ground shook, and Sam was terrified. Castiel's frustration with this human was getting out of hand. "Don't be afraid," he said, pulling his wings in. The air calmed, the room was still. "Why are you so against this, Sam? This is the best option."

"I..." He ran a hand through his hair, looking away. All body language indicated that Sam was ashamed of what he was about to confess, and Castiel schooled his features to look receptive. "It's just... you're, you know. You. You're an angel. And I'm - I mean, Azazel's blood is in me," he said, finally, fixing his eyes on Castiel's hand. Castiel sensed the sudden quickening of his heart, the beat of blood in his veins. Sam licked his lips. "Ruby aside, I have demon blood. I've always had it. I'm not - "

"Worthy?" Castiel finished. Sam reddened, ducking his head and hiding beneath a curtain of hair.

It was truly incredible to Castiel that someone with so bright a soul, who strove every day to save lives and rid the world of evil, disregarding any rest or recognition for himself, could see himself in such a negative light. Such was the work of angels. "Sam," he sighed, stepping closer. "I won't lie to you; you have been cursed, damned before you were born."

"I know," Sam said softly, without bitterness. To Sam, it was fact, irrefutable truth. But Sam was wrong - about himself, about his destiny, about a great many things.

"There is a saying among humans, is there not? That my Father helps those who help themselves?" reminded Castiel gently. Sam looked at him with wide eyes. "You have the ability to change your curse into a blessing. With my guidance, you shall not fail. Now," he extended his bleeding hand to Sam. "Drink."

Sam hesitated, then slowly brought the hand to his lips. "Okay," he whispered. "Okay."

The first press of Sam's tongue was tentative, delicate, almost afraid. Once he had gotten a taste, however, he grew bolder, fastening his lips to the skin of Castiel's palm and drinking in earnest. He was gentle, the slow sucking of his mouth hypnotic in its rhythm, with soft moans of pleasure following afterwards. His eyes were closed, as if in prayer. It was an unconventional sort of reverence, but one that Castiel would accept gladly. It was the same sort of awe that Sam had displayed when they first met, but it was so much more potent and pleasing now that he was free of demon blood.

Castiel took a moment to study Sam's physical features. The slant of his eyes, his strong cheekbones, his tough yet gentle hands - all were well-suited to him. Destiny had given Lucifer a very fine vessel, aesthetically pleasing and noble in appearance. Had he pursued the path of Azazel's Boy King, he would have gained an immense and extremely dedicated following. Any human would have died for him, any demon would have given himself up. Castiel wondered if, in that potential timeline, angels would have been immune to the pull of the Boy King. Eventually, he pulled his hand away. "How do you feel?"

Sam was swaying lightly on his feet, mouth open, eyes hazy. "I..." he started, licking his lips. There was real color in his cheeks, and a slight sheen to his skin, like his soul was glowing, permeating the edges of the visible spectrum. "I don't know," he laughed, looking to the ceiling. Looking to Heaven. "Good? Um, kind of... light, I suppose. Not heavy." He took a deep breath, and smiled. "Really good."

"Good," Castiel echoed. "I am glad. We shall begin."

"Wait - Cas," Sam interrupted.

"What is it?"

"I just wanted - thank you," he said quickly. "Thank you."

Castiel tilted his head, curious. "For what?" Sam shrugged.

"Saving Dean, and now this, it's... thank you, so much." He smiled again, with dimples, and something in Castiel's chest grew tight. Sam's smile was very beautiful. He projected an air of great warmth, and kindness, and control, and Castiel was drawn to him. His palm tingled at the memory of Sam's lips upon it, and for a split second, he felt the urge to kiss it, or to kneel at Sam's feet and worship him the same way that Sam had worshipped him.

"Do not thank me yet, Sam," he said quietly, even as he struggled to process this new tide of emotion. In that one moment, he had burned with an intense desire to venerate Sam, to completely and utterly give himself over to him, to Azazel's prince and Lucifer's vessel. He had never felt that way before, not even about his own Father. It disturbed him, his vessel's heart pulsing unevenly. _What have you done to me, Sam Winchester, that I feel so strongly for you. _

"What powers do you possess?" he asked, shoving all unsettling thoughts aside for the time being. Azazel's blood should have granted his "children" one power each; Castiel's working hypothesis was that Sam had possessed the power of an extremely compelling nature, the ability to make people want to obey him, or follow him, or love him. It was a logical power for a king to possess, an augmentation of his own natural charisma.

"Uh, just the psychic exorcism. Before, I used to get visions; they stopped coming after Dean killed the yellow-eyed demon."

"Anything else?" Castiel pushed.

"No. I mean, one time I moved a dresser that was blocking a door, but it was pretty much one power per person. Apart from Ava," he commented.

"How was she different?"

"She - I don't know how - she got visions, like me, but when I saw her again in Cold Oak, she could control the demons in the surrounding area. And Jake," he said, remembering, "Jake had super strength, but at the Hell's Gate, he used Andy's mind control on Ellen."

"How?" Castiel demanded, a despairing sort of sound forced from his vocal chords.

"I don't know," Sam said again, "they just - they stopped fighting it, fighting the yellow-eyed demon's plan and gave in, and - learned all these fancy new mind tricks."

"And did you ever stop fighting it?" Castiel asked, even though he already knew the answer.

"No," Sam insisted, shaking his head. "I fought him every step of the way. I died at Cold Oak because I refused to give in to his game." He was so earnest, and Castiel's heart broke, because he was _wrong_.

When Sam allied himself with the demon Ruby, listened to her advice and drank her blood, he had given in to Azazel's game. He had opened his mind to the influence of demon blood, and all of his latent powers were surfacing. Psychic exorcisms, telekinesis, a compelling nature - he had them all. He was _using_ them all, even if he didn't realize it. Castiel suspected that he had been using his powers for much longer than Sam thought. Small wonder that Sam was more powerful than anyone had expected. He had a veritable mental arsenal, and he had been training with his mental weapons for years.

"Cas?" Sam asked concernedly. "Are you alright?" He stepped up to Castiel, and cupped his cheek, gently running a thumb across his cheek. "You're crying."

"It's nothing," said Castiel in a watery voice. He couldn't look away; deep within Sam's eyes there was pulsing gold, like a beating heart. Castiel couldn't look away if he tried. He was already under Sam's spell, and he hadn't even noticed it until it was too late. Castiel was doomed.

But then, so was Sam. And if Castiel was going to Fall, he could think of no better reason than the one standing before him.

"I will be fine," he assured Sam, wiping his eyes. "Let us begin your training."

The wheel of destiny turned, its stones grinding with the force of change. There had once been a Plan, set down by God. Then, there had been a plan instigated by the forces of Hell. Now there was no plan, but the chaos of an uncertain future, and the impending cataclysm ahead.


End file.
